Oh I agree. There's not a whole lot they can do to improve the reliability of UPnP overall. But there are a lot of things they could do to improve the multiplayer experience when it fails.It does help a lot when implemented properly though, and there are are enough testimonials in there that show it. Port forwarding has helped for eons to players in many other peer to peer based games, not just Elite. Having said that it is important to remind that there will always be exceptions and there are certain home or private network setups that have limitations such as cgnat etc.
As for what can FDEV do, well, the UPnP protocol that peer to peer architecture is based on is inherently unreliable (not just for Elite), not much FDEV can do there except completely change and revamp the whole networking architecture for Elite. The main mitigation for most of those peer to peer games happens to be port forwarding.
The biggest pain point is being unable to rejoin a session once it's lost, and the associated mission failure that takes place when that occurs.
If they let us do that, and let us revive our teammates with medpacks, that would resolve about 90% of the current pain that is felt in multiplayer.